Gov. Cuomo wants you to blame train motorman William Rockefeller for Sundays deadly Metro-North wreck. Well, blaming a sleepy-headed driver makes life a lot easier for Cuomo and the state-run MTA. But Rockefeller wasnt in charge of the railroad — whose managers are supposed to protect riders from any one employees failures.

Throwing Rockefeller in jail may (or may not) be justified, but it wont fix the MTAs catastrophic failures here.

Yes, speed matters. Investigators suggest that Rockefeller was sleeping, dozing, or "dazed" as he sped toward Grand Central early Sunday morning. He approached the dangerous Spuyten Duyvil curve at 82 mph when he should have been slowing to 30.

But does speed matter "more than anything"? Thats what the governor keeps saying. "I think its going to turn out to be about speed more than anything and the operators operation of the train," Cuomo said Monday. Later that day, he insisted, "Extreme speed was a central cause."

The problem here is that railroads have always known of the danger that an inattentive or reckless driver poses. Its no surprise that staring at a stretch of rail alone at a time when normal people are asleep is boring.

So railroads devised ways to keep drivers awake and alert. These devices should stop the train if the driver wont or cant become awake and alert.

Back in 1929, the Pennsylvania Railroad was spending $16 million to install automatic controls to stop a train when the engineer failed to respond to a danger signal. Even before that, the old New York Central (whose territory spanned some of the MTAs tracks today) had already installed similar warning devices, plus whistles to warn a driver to pay attention.

And Metro-North has long had newer technology that warns a motorman — via a deafening whistle — to pay attention or slow down, or the train will stop for him.

Nearly two decades ago, in 1996, Metro-North touted one auto-system, noting that "a pretty shrill alarm" would go off if a train were to exceed allowed speed. And if the driver didnt heed the call, "the train will stop itself," The New York Times reported back then.

So why didnt it work? It turns out that the Metro-North trains dont have the speed-governing technology on this stretch of the Hudson line, and only have the whistle-alert technology on northbound Hudson trips. When the train is going south, the locomotive pushes the passenger cars rather than pulls it. So its in the back, far away from the driver (who controls the locomotive electronically from the front), the Times reported Wednesday.

That means that passengers are safer going north than south — a rather bizarre situation.

And theres no excuse for it.

The MTAs been bitten by the problem before. Back in 1988, an engineer crashed one empty train into another and died, likely due to inattention (the autopsy didnt show a heart attack). At the time, the Times reported that "experts" wondered why the train was going at 60 mph when it shouldnt have been, and why it hadnt stopped automatically.

Plenty of current Metro-North managers were around back then. So why hasnt the problem been fixed?

Some will scream money. But the MTA has money. It spends far too much of it on dangerously unaffordable pension and health benefits — $194 million at Metro-North alone, up 49 percent in four years. The MTA had enough money to pay Rockefeller $145,533 last year, according to SeeThroughNY payroll data..

Thats money that could go toward first-class infrastructure. But neither Cuomo nor his predecessors has been willing to address the issue.

One likely culprit is simply managerial and supervisory incompetence. Remember, Metro-North already suffered a serious derailment this year, in May, with two people critically injured. That, too, was likely human error — human failures to properly inspect and maintain tracks. Also this spring, a train struck and killed a track worker — because an inexperienced signalman opened a closed track.

These recent problems remind us: Who was supervising Rockefeller — and who, or what, was monitoring speeds on a regular basis toward Spuyten Duyvils perilous curve?

Hmm: According to its budget, Metro-North was supposed to have 28 safety administrators by 2012, up from 18. Instead, it had just 17 such workers last year. Now it says it needs 33.

Either the railroad doesnt have enough of these folk, or hasnt for a while. Or it has the wrong ones and cant fire them.

Rockefeller screwed up. But his screwup shouldnt have cost four lives — and were lucky it wasnt more.